Production and treatment of filaments, yarns, ribbons, films, and other materials made of or containing cellulose esters or ethers



Patented Dec. 31, 1935 UNITED STATES PATENT oFHsE William Ivan Taylor, Spondon, near Derby, England,

assignor to Celanese Corporation of America, a corporation of Delaware No Drawing. Application July 14, 1931, Serial 6 Claims.

This invention relates to improvements in the production and treatment of filaments, threads, yarns, ribbons, films or other materials, made of or containing cellulose acetate or other cellulose esters or ethers.

In U. S. Patent No. 1,709,470 processes are described for increasing the resistance of cellulose acetate filaments to the delustering action of hot or boiling aqueous media, which consists in stretching the filaments whilethey are in the fully set and finished condition. The specification further describes how such stretching may be assisted by the use of certain assisting agents, for example by applying to the filaments a 20% aqueous solution of acetone or of ethyl alcohol. Further in U. S. application S. No. 378,684 dated 16th June, 1929, processes are described whereby stretching of cellulose acetate filaments or threads, or filaments or threads of other organic derivatives of cellulose to an extent of 10%, 30% or even 100% or more of their length may be conducted while the filaments or threads are travelling from one point to another, for instance while they are travelling from a dry spinning metier to a winding device. The said specification gives numerous instances of suitable assisting agents for use in such a process.

In U. S. application S. No. 403,140 dated 28th October 1929, there is described how improved results may be obtained by using as assisting agents relatively concentrated neutral organic solvents or strong swelling agents, for example diacetone alcohol, ethyl lactate or diethyl tartrate in aqueous or alcoholic solution of a concentration of 25-65% strength. The said specification further describes how the properties and particularly the elasticity of the products may be improved by applying a treatment with the relatively concentrated neutral organic solvents or strong swelling agents without stretching the filaments or other products, for example by efiecting the treatment under a tension only sufficient to.prevent shrinkage, or under conditions in which shrinkage ocours.

The present invention is also concerned with similar processes, in which filaments, yarns, or other products made of or containing cellulose acetate or other cellulose esters or ethers are improved as regards their properties, and in particular their extension and/or tenacity, or are conditioned. I have now found that improved results may be obtained by the use of substances which at ordinary temperatures do not exert a solvent or strong swelling action upon the cellulose derivatives, but which are capable of swelling In Great Britain September 8,

or plasticizing, or even dissolving the cellulose derivatives at relatively high temperatures. Such agents are for example glycerin, glycols, for example ethylene glycol, diethylene glycol, propylene, glycol, trimethylene glycol, 1.2- and 1.3- 5

butylene glycols, or other polyhydric alcohols or derivatives thereof, e. g. mono-ethers of glycerine.

I prefer to employ the said agents at relatively elevated temperatures, for example at temperatures at which they do exert a softening, swelling, l0

plasticizing, or solvent action, but the invention is by no means limited to such temperatures. With glycerin very good results are obtained by treating the filaments, yarns, or other materials at temperatures of 120 to 170 C., and particularly at 15 temperatures of 140 or 150-l60 C.. With diethylene glycol, on the other hand, very goodresults are obtainable at temperatures of 75-90" C.

As in U. S. application S. No. 403,140 dated 28th October 1929, the filaments or other prod- 20.

ucts while under the action of the said agents may be stretched for example, to an extent of 20, 50, 100, or even 200% or more of their previous length, the stretch which may be imparted being primarily dependent upon the extent to which 25 the filaments or other products are softened in the treatment with the glycerin or other polyhydric alcohols 'or' other agents. The invention further includes the treatment of the materials with the said agents under such conditions that 30 shrinkage occurs, or under a tension sufficient to prevent shrinkage. In the case of treating materials without stretching I find that there is a very considerable improvement in their extension,

relatively small improvement in their tenacity. On the other hand by applying a stretching treatment the tenacity may be considerably increased.

The action of the glycerin, glycols or other 40 polyhydric alcohols, or other agents to be used in accordance with the present invention, may be modified by means of substances, such as Water, benzene, or other hydrocarbons, alcohols, -or the like, which are comparatively inert towards the cellulose derivative or by means of substances which exert a solvent or strong swelling action upon the cellulose derivative, as for example the Various agents mentioned in U. S. Patent No. 1,709,470 and U. S. applications S. Nos. 378,684 dated 16th July, 1929, and 403,140 dated 28th October, 1929, e. g. acetic acid, formic acid, lactic acid, diacetone alcohol, acetone, the monoand di-ethers of olefine glycols or polyolefine glycols, for instance the monoand dimethyl and ethyl ethers of ethylene glycol, dioxane, the mono-methyl and ethyl ethers of propylene glycol and the mono-ethyl ethers of diethylene glycol, etc., phenols, dichlorethylene, ethyl lactate, diethyl tartrate and the like. Such agents may, for example, be mixed with the glycerin, glycols or like agent or may be carried by the filaments or other products, which may for instance be spun from a solution containing such an agent undersuch conditions as to retain the agent, or the materials may be impregnated therewith prior to treatment with the glycerin, glycol or like agent. When employing high temperatures in the treatment with the glycerin, glycol or the like, and when it is desired to employ such an additional agent, it is preferable to employ an agent which is comparatively non-volatile, as for example ethyl lactate, diacetone alcohol or diethyl tartrate. The hot treatment with glycerin or other suitable agent may be conducted so that such additional solvent or inert agent'is completely volatilized or partially volatilized during the treatment or remains in the product.

'I 'He treatment according to the present in-.

vention may be applied to the materials in yarn, thread, filament, or other form, for example on bobbins, in hanks, on beams or the like, or while the materials are travelling from point to point,

for example from bobbin to bobbin, or from a dry or wet spinning machine to a winding or twisting device. In the case of treating the materials in hank form or on bobbins or the like, rigid supports may be provided so that no shrinkage takes place, or on the other hand collapsible swifts or bobbins may be used so that shrinkage is permitted. As stated above however, I prefer to carry out the present processes together with a stretching of the filaments or other products, and to this; end the materials during or after treatment with the glycol, glycerin or other agent may, for example, be carried successively round rollers rotating at in-' creasing peripheral speed. Filaments or threads may, for example, be passed from a dry or wet spinning machine, with or without previous twisting, or from a bobbin to a bath consisting.

of glycerin or other suitable agent, and thence to a suitable winding apparatus. When starting up, the filaments or threads may be carried over the top of the glycerin or other bath and be subsequently immersed in the bath by lowering suitable guides adapted for this purpose.

Where stretching is desired suitable rollers or other devices may in addition be provided. After passage through the glycerin or like bath the filaments, threads, or the like may be passed over suitable guides adapted to remove excess of glycerin or other agent, or through suitable rollers which will squeeze out the excess, and may then be washed by means of a bath, spray or otherwise, and finally carried to a winding or twisting device. It is especially advantageous to twist by the cap spinning method, since the ballooning of the filaments or threads in such a process serves to dry the wet threads or filaments.

The following examples illustrate the invention but are not to be considered as limiting it in any way:-

Example 1 A ning apparatus at a speed of 10-25 or even up to '75 metres a minute are carried through a bath of glycerin heated to a temperature of 140-160 C., the length of immersion being 8-15 or 25 feet or more. Before passing through the bath the filaments are carried round a roller 5 rotating at the speed of travel of the filaments 0r threads, and after passage through the bath they are carried round another roller rotating at a higher peripheral speed, for example 70, or in excess of that of the first roller. 10

Example 2 Cellulose acetate yarn is passed through a bath of glycerin maintained at a temperature of about 155-160" C., at a speed of 8-12 metres a 15 minute, the length of the bath being, for example 6-9 feet. As in Example 1 the yarn is carried successively round rollers rotating at different peripheral speeds so as to insert therein a' stretch, for example a stretch of 80%, on 20 the original length of the yarn.

Example 3 A bath of diethylene glycol is prepared and maintained at a temperature of 80-85- C. The 5 yarn is passed therethrough and stretched as described in Example 2 above.

Example 4 A bath of glycerin containing 10% ethyl lac- 30 tate is prepared and is maintained at a temperature of -150 C. The yarn is passed therethrough and stretched as described in Example 2.

Example 5 35 A yarn is spun from a solution of cellulose acetate containing 15% of ethyl lactate on the weight of the cellulose acetate, the spinning being conducted under such conditions that 40 about 10% ethyl lactate on the cellulose acetate remains in the yarn. The said yarn is there- I after treated as described in Example 2 above, with the exception that the bath is maintained at a temperature of 140150 C. The stretch 45 obtainable is much greater than in Example 2.

Example 6 A hank of cellulose acetate yarn is immersed in glycerin maintained at 160 C. for a few 50 minutes. The yarn is permitted to shrink, thereby increasing its extension.

While the invention has been described above with particular reference to cellulose acetate, it is broadly applicable to materials made of or 65 containing any other cellulose ester or ether, for example cellulose formate, cellulose nitro acetate, cellulose propionate, cellulose butyrate, ethyl cellulose, methyl cellulose, or benzyl cellulose.

What I claim and desire to secure by Letters 00 Patent is:--

1. Process for improving the tensile properties of artificial filaments, threads, yarns, ribbons, films and like materials having a basis 01' an organic derivative of cellulose, which comprises swelling said materials by treatment with a substance selected from the group consisting of glycerine and diethylene glycol, at temperatures of 120" to C. and '75 to 90 C., respectively, and stretching the materials from 65 to 80% of 70 their length in the presence of the treating substance, whereby the tenacity of the materials is increased at least 30%.

2. Process for improving the tensile properties of artificial filaments, threads, yarns, ribbons,

films and like materials having a basis of cellulose acetate, which comprises swelling said materials by treatment with a substance selected from the group consisting of glycerine and diethylene glycol, at temperatures of 120 to 170 C.

and to C., respectively, and stretching the materials from 65 to 80% of their length in the presence of the treating substance, whereby the tenacity of the materials is increased at least 30%.

3. Process for improving the tensile properties of artificial filaments, threads, yarns, ribbons, films and like materials having a basis of an organic derivative of cellulose, which comprises swelling said materials by treatment with glycerine at a temperature of to C. and stretching the treated materials substantially 80% of their length in the presence of the glycerine, whereby the tenacity of the materials is increased at least 30%.

4. Process for improving the tensile properties of artificial filaments, threads, yarns, ribbons, films and like materials having a basis of cellulose acetate, which comprises swelling said ma-.- terials by treatment with glycerine at a temperature of 120 to 170 C. and stretching the treated materials substantially 80% of their length in the presence of the glycerine, whereby the 'tenacity of the materials is increased at least 30%.

5. Process for improving the tensile properties 5 of artificial filaments, threads, yarns, ribbons, films and like materials having a basis of an organic derivative of cellulose, which comprises swelling said materials by treatment with diethylene glycol at a temperature of 75 to 90 C. 10 and stretching the treated materials substantially 65% of their length in the presence of the diethylene glycol, whereby the tenacity of the materials is increased at least 30%.

6. Process for improving the tensile properties 15 of artificial filaments, threads, yarns, ribbons, films and like materials having a basis of cellulose acetate, which comprises swelling said materials by treatment with diethyleneglycol at a temperature of '75 to 90 C. and stretching the 20 treated materials substantially 65% of their: length in the presence of the diethylene glycol, whereby the tenacity of the materials is increased at least 30%.

. 26 I WILLIAM IVAN TAYLOR. 

